Sculptural works in glass are still few and far between, principally due to the prohibitively costly and singularily unpredictable nature of glass. Like hot glass blown by the craftsman, the finished product is very much restricted to the nature of glass. Even one of the greatest glass artists in America, whose skill and variation is astounding, rarely breaks from the organic flowing nature of liquid glass in his finished forms; most often referring to the fluid brilliance of choral reef plant and sealife inhabitants or the vivid brilliance of flowers. As a sculptor, this restriction makes great art in glass difficult as the artist is unable to go beyond these boundaries as with paint, metal, clay etc. - the medium predicates the outcome. Cold glass has many limitations also as the colour is already dictated (unlike blown glass), coming in sheets of colour with some ground colours that can be decoratively melted (fused) into the sheet glass. The outcome is still limited in finish, unlike the tremendous variations of colour paint lends itself to. So too the shape. The cold glass artist must cut a pattern, much like a dress designer, allowing for the fall and altered shape over a desired form, called slumping. Thus creating the colours and perhaps layers of glass (melting/fusing) at high molten temperatures then refiring the glass over the desired shape (slumping) at cooler temperatures like thick honey. At either of these stages, quite apart from the delicate and skillful stage of cutting the shape with glass cutters, the glass may crack, bubble, or burn flare spots of foreign matter between the layers. So glass works will remain rare and expensive one-off works in sculpture for some time to come.